A company founded by several MIT engineers launched free Internet Explorer and Firefox plug-ins Wednesday that reveal dangerous Web sites listed by popular search engines.
With the plug-ins installed, users see green, yellow, or red tags beside hits in search results on Google, MSN, and Yahoo, said Boston-based SiteAdvisor. The tags — red represents sites that heavily spam visitors, host spyware and adware, or hijack browser home pages — give users a heads-up before they click on a link.
The company’s ratings were with the help of automated Web spiders, which crawled the millions of sites that represent more than 95 percent of the Internet’s total traffic. Nearly half a million downloads were analyzed for spyware and other malicious code, and 1.3 million registrations were logged using unique e-mail address to track spam from each site source.